Most computer consumers are urging the industry to provide an increase in the rate of data communication (e.g., Internet, WANs, LANs, token ring, etc.) over conventional communication media (e.g., copper wire, cable, wireless, etc.). Yet, the personal computer (PC) market and the PC consumer will generally not accept an increase in performance at the expense of a severe increase in system cost. Therefore, it is advantageous for the cost of newly designed data communication systems (e.g., ADSL modems, cable modems, wireless systems, V.90 modems and the like) to remain flat or even decrease over time while simultaneously accommodating improved performance.
Historically, the modem integrated circuit (IC) industry has responded to the desire for enhanced performance by designing and manufacturing much more complex digital signal processors (DSPs) that can provide more MIPS (millions of instructions per second) or use by modem algorithms. While these faster and more complex DSP ICs may significantly enhance performance, many of these new DSP products are too expensive or too power-intensive to use within the sub-$1000 PC market or within the growing number of low-cost, low-power, embedded or hand-held modem systems. In short, the market will not accept incrementally adding up to several hundred dollars in modem DSP hardware to a PC or hand-held device where such addition increases the overall cost of these devices by 20% or more. Furthermore, many older, low-cost, existing DSPs simply do not have the MIPS capability to perform all the requisite data pump functions needed in modern DMT modem systems. Therefore, it has been very difficult to offer the consumer increased data communication rates at reduced costs when using conventional modem architectures that execute all modem operations on a DSP engine.
Some systems have opted to entirely eliminate the DSP from the modem solution to reduce cost. These systems, referred to as “soft modems”, are simply a collection of software functions or algorithms that are placed into the general purpose global memory of a PC and executed entirely on the host processor of the PC (e.g., PowerPC™ 604 or Pentium™ II). Many of these “soft modem” solutions are being provided to the market at a price that is cheaper than the base manufacturing costs of many modern DSPs. However, the soft modem solution consumes a significant portion of the MIPS of the host processor, whereby the host processor is generally too busy processing incoming data to quickly perform real-time tasks for the current computer user. Therefore, while the soft modem is a significant advance and very useful in some applications, it is not a viable solution for every consumer in all situations.
Therefore, a need exists in the industry for a system that provides adequate high-end performance (e.g., enough performance to more efficiently implement higher rate communication protocols like asymmetric digital subscriber line (ADSL), cable modem, and G.lite implementations), at a cost that is attractive to consumers, in a flexible manner, without consuming user-noticeable amounts of host CPU processing power.